Abstract:

A process for the separation of bitumen oil from tar sands and the like.
Slurry is supplied to a mixing chamber of a jet pump at an input end of
the process. The slurry is agitated within the jet pump to effect a
partial to full phase separation of the oil fraction from the solids
fraction of the slurry. The partially to fully separated slurry is
discharged into a pipeline and later into a hydrocyclone to effect a
second phase separation of the slurry. One or more hydrocyclone
separators may be used to separate the bitumen oil and liquid from the
solids fraction.

Claims:

1. A process for phase separation of tailings comprising a solids fraction
and an oil and water fraction, the process comprising the steps
of:supplying the tailings to a mixing chamber of a jet pump, the jet pump
being supplied with wash fluid from a power source;agitating the tailings
within the mixing chamber of the jet pump to effect a partial to full
phase separation of the oil and water fraction from the solids fraction
of the tailings; anddischarging of the partially to fully separated oil
and water fraction and solids fraction of the tailings from the jet pump.

2. The process of claim 1 in which the jet pump operates at a Reynolds
number above 250,000.

3. The process of claim 1 in which the slurry is supplied from a hopper,
wherein the hopper is free of phase separation devices.

4. The process of claim 1 in which the partially to fully separated oil
and water fraction and solids fraction of the tailings is discharged from
the jet pump into a phase separation device.

5. The process of claim 1 in which discharging further comprises
discharging the partially to fully separated oil and water fraction and
solids fraction of the tailings from the jet pump into a pipeline for
continued separation through mixing and contact with the wash fluid
within the pipeline.

6. The method of claim 5, further comprising discharging the partially to
fully separated mixture of the oil and water fraction and the solids
fraction of the tailings from the pipeline into a phase separation device
to effect a second phase separation of the tailings and produce a first
output stream comprising the solids fraction and a second output stream
comprising the oil and water fraction.

7. The process of claim 6 further comprising repeating the process steps
of claim 6 to yield a solids fraction and chemically conditioning the
solids fraction with calcium oxide.

8. The process of claim 6 further comprising treating all or portions of
the first output stream with a thermal screw to produce a solids fraction
free of any residual water and hydrocarbons.

9. The process of claim 6 in which the phase separation device comprises a
hydrocyclone.

10. The process of claim 1 in which the tailings comprises tailings from a
mining or drilling operation.

11. A method for treating a mixture comprising tailings, the mixture
having a solids fraction, a hydrocarbon fraction, and a water fraction,
the method comprising the steps of:supplying the mixture to a mixing
chamber of a jet pump;supplying a primary flow to an input of the jet
pump; andoperating the jet pump using the primary flow to agitate the
mixture and propel an agitated mixture from the jet pump to effect at
least a partial phase separation of the hydrocarbon fraction from the
solids fraction and the water fraction.

12. The process of claim 11 in which the agitated mixture is discharged
from the jet pump into a phase separation device.

13. The method of claim 11 in which the agitated mixture is discharged
from the jet pump into a pipeline for continued separation through mixing
and contact with the wash fluid within the pipeline.

14. The method of claim 13 further comprising discharging the agitated
mixture from the pipeline into a phase separation device to effect a
second phase separation of the agitated mixture and produce a first
output stream comprising the solids fraction and a second output stream
comprising the hydrocarbon fraction and the water fraction.

15. The method of claim 11 in which the mixture is supplied from a hopper,
and in which the hopper is free of phase separation devices.

16. The method of claim 11 in which the jet pump operates at a Reynolds
number above 250,000.

17. The method of claim 14 in which the phase separation device comprises
a hydrocyclone.

18. A process for phase separation of a mixture comprising tailings and
having a solids fraction and a hydrocarbon fraction, the process
comprising the steps of:supplying the mixture to a mixing chamber of a
jet pump;supplying a primary flow to an input of the jet pump;
andoperating the jet pump using the primary flow to agitate the mixture
and discharge the agitated mixture from the jet pump to effect at least a
partial phase separation of the hydrocarbon fraction from the solids
fraction.

19. The process of claim 18 in which the agitated mixture is discharged
from the jet pump into a phase separation device.

Description:

[0002]This invention relates to a method for separating bitumen oil from
tailings.

[0003]The current industry practice for extracting bitumen from tar sands
and the like is the hot water process, utilizing aggressive thermal and
mechanical action to liberate and separate the bitumen. The hot water
process is typically a three-step process. Step one involves conditioning
the oil sands by vigorously mixing it with hot water at about 95 degrees
Celsius and steam in a conditioning vessel to completely disintegrate the
oil sands. Step two is the gravity separation of the sand and rock from
the slurry, allowing the bitumen to float to the top where it is
concentrated and removed as a bitumen froth. Step three is treatment of
the remainder slurry, referred to as the middlings, using froth
floatation techniques to recover bitumen that did not float during step
two. To assist in the recovery of bitumen during step one, sodium
hydroxide, referred to as caustic, is added to the slurry in order to
maintain the pH balance of the slurry slightly basic, in the range of 8.0
to 8.5. This has the effect of dispersing the clay, to reduce the
viscosity of the slurry, thereby reducing the particle size of the clay
minerals.

[0004]A problem related to the industry practice is that the addition of
caustic, coupled with the vigorous and complete physical dispersal of the
fines, produces a middlings stream that may contain large amounts of well
dispersed fines held in suspension. The recovery of bitumen from these
middlings stream increases with the increase in the fines concentration
over time. In addition, the middling stream that remains following step
three, referred to as the scavenging step, poses a huge disposal problem.
Current practice for the disposal of the resultant sludge involves the
pumping of the sludge into large tailings ponds. This practice poses
serious environmental risks.

[0005]The industry practice for the extraction of bitumen from oil sands
has been to maximize the recovery of bitumen while minimizing the
production of sludge, which require treatment and disposal. The industry
practice typically provides for a bitumen recovery of between about 80%
and 95% of the total amount of bitumen contained in the oil sands. Lower
bitumen recoveries are experienced with oil sands of high fine material
and low bitumen contents. To increase bitumen recovery, methods have
arisen to reheat and recycle water recovered during the solids
de-watering phase to re-expose the suspension of dispersed fine material
to the conditioning bath, whereby the dispersed fine material may undergo
further froth floatation treatment for bitumen recovery.

SUMMARY OF INVENTION

[0006]A process for the separation of bitumen oil from tailings is
disclosed. In an embodiment, slurry comprising tailings is supplied to a
mixing chamber of a jet pump at an input point of the separation process.
The slurry is agitated within the jet pump to effect a partial to full
phase separation of the oil and water fraction from the solids fraction
of the slurry. One or more phase separation devices, for example
hydrocyclone separators, may be used to separate and concentrate any
remaining residual bitumen oil and liquid from the solids fraction.

[0007]In some embodiments, the process distinguishes itself from others in
that it does not require the use of elutriation vessels, clarifiers,
separators, baths or similar devices to condition and/or to separate the
oil and liquids from the solids fraction. Bitumen separation may be
achieved during mixing within the jet pump and within the pipeline. The
extraction of bitumen oil from the tar sands and the release of the solid
particles from the oil sand matrix continues in the slurry exiting the
jet pump as the jet pump transports the slurry to the material separation
and classification process.

[0008]Pre-conditioning of the raw material is not a requirement of this
process, greatly reducing the infrastructure of the plant. Rather the
solids fraction of the slurry is physically and/or chemically conditioned
by the wash fluid that can consist of a cold or hot water, or a solvent
or a water chemically treated or a mixture of all. In some embodiments,
the use of elutriation vessels, clarifiers, separators, baths or the like
may be replaced with hydrocyclone separators. The hydrocyclone separators
are designed to separate and classify the slurry stream using centrifugal
forces into two stream fractions consisting of water and oil and solids.
The processes disclosed herein can be applied to separate bitumen
attached to any type of solid. Further, multiple wash step loops are
possible to maximise bitumen separation and recover, or to achieve any
level of treatment recovery desired.

[0009]An apparatus according to an aspect of the invention comprises
hopper, motive pump, jet pump, pipeline, and hydrocyclone separator. The
hopper is designed to receive the raw material and can be shaped as a
cone bottom vessel or alternatively equipped with a mechanical auger
designed to convey material to the inlet of the jet pump. The motive pump
is designed to supply the high pressure fluid necessary to operate the
jet pump which by use of a nozzle within the jet pump the fluid is
converted into a high velocity jet to produce a vacuum within the mixing
chamber of the jet pump to suction the tar sands into the inlet of the
jet pump. Further aspects of the invention are described in the detailed
description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]An exemplary embodiment is now described in detail with reference to
the drawings, in which:

[0011]FIGS. 1A-1F are flow charts of a process of separation and recovery
of bitumen from tar sands in which the proposed invention may be used, in
which FIG. 1A shows a first wash treatment process of the input slurry
with water, FIG. 1B shows wash steps with solvent on the heavier output
from the steps of FIG. 1A, FIG. 1C shows wash steps with water on the
heavier output from FIG. 1B, FIG. 1D shows a first oil\water separation
treatment process on the lighter output from the process of FIG. 1A, FIG.
1E shows process steps for the treatment of de-watered solids using a
thermal screw, FIG. 1F shows treatment of recovered wash water;

[0012]FIG. 1G is a flow chart that shows the interrelationship of FIGS.
1A-1F;

[0013]FIG. 2 is a schematic of the feed hopper, jet pump, pipeline and
hydrocyclone according to the invention; and.

[0014]FIG. 3 is a detailed schematic of a jet pump for use in a method
according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0015]With reference to FIGS. 1A-1F, an overview of a process for the
separation and recovery of bitumen oil from tar sands and the like is
described. Tar sands, also referred to as oil sands, are a matrix of
bitumen, water, and mineral material. The bitumen consists of viscous
hydrocarbons, which acts as a binder for the other components of the oil
sand matrix. A typical deposit of oil sand will contain about 10% to 12%
bitumen and about 3% to 6% water. The mineral material consists of rock,
sand, silt and clay. Clay and silt are considered to be fines. Mineral
material can contain about 14% to 30% fines. Although it is understood
that the described process and apparatus may be applied to removing oil
from any type of particulate material, in accordance with a preferred
embodiment of the invention, the process and apparatus are applied to
separating and recovering bitumen oil from tar sands, such as that
derived from mining or drilling operations.

[0016]As shown in FIG. 1A, tailings 1 from, for example a mining or
drilling operation, may be fed into a receiving hopper 2 via preferably a
belt conveyor 3 or alternatively via a front end loader 4 at an input end
of the tar sands separation process. At the input end, the unprocessed
tar sands have undergone little or no processing, and no phase
separation. The belt conveyor 3 features a troughed belt on 20 degree or
greater idlers and are readily available in the industry. The receiving
hopper 2 may be supplied with a mechanical grinder 5 and has its
discharge coupled to a jet transfer pump 6. The mechanical grinder 5 is
also readily available in the industry. The jet pumps 6 is also readily
available in the industry, such as those manufactured by Genflo Pumps,
but some care must be taken in choosing the jet pump, and it is preferred
to use the jet pump shown in FIG. 3. The jet pump 6 should operate at a
high Reynolds number, above 250,000, and preferably in the order of
650,000 to 750,000. Such a Reynolds number may be obtained by a
combination of high pressure, for example 80 psi or more, and a
sufficiently long mixing chamber, as for example shown in FIG. 3. All jet
pumps described in this patent document preferably have this
configuration.

[0017]As the tar sands enter the receiving hopper 2 they may be
mechanically ground, preferably using a mechanical grinder 5 to produce
particles 50 mm in size or smaller. The jet transfer pump 6 at the
respective base of cone 7 of the receiving hopper 2 mixes the ground tar
sands 1 with a hot water stream from line 8 to produce a hot slurry
mixture in line 9 which is passed into a first hydrocyclone separator 10.
Centrifugal forces within the first hydrocyclone separator 10 separate a
large portion of the solids from the bitumen oil and water mixture. The
solids are removed from the bottom of hydrocyclone separator 10 and
gravity discharged into cone bottom hopper 11. The remaining slurry
mixture, comprising primarily of the bitumen oil and water, in line 12,
is gravity discharged into a centrate collection tank 13. Any residual
solids in this stream settle to the bottom of the centrate collection
tank 13. The oil and water are removed from the top at point 14 of the
centrate collection tank. A further jet transfer pump 15 located at base
16 of the centrate collection tank 13 removes and mixes the solids with
the hot water stream in line 17 and passes it through line 18 to a second
hydrocyclone separator 19. Centrifugal forces within the second
hydrocyclone separator 19 separate the remaining portion of the solids
from the oil and water fractions. The solids are removed from the bottom
of hydrocyclone separator 19 and gravity discharged into the cone bottom
hopper. A jet transfer pump 20 located at base 21 of the cone bottom
hopper 11 removes and mixes the solids with the hot water stream in line
22 and passes it through line 23 to the inlet of centrifuge 24.
Optionally, the water wash step can be repeated multiple times with each
step identical to the preceding step.

[0018]As shown in FIG. 1B, solids removed from the bottom of the cone
bottom hopper 11 are de-watered using centrifuge 24, preferably a basket
or solid bowel centrifuge. Alternative mechanical dewatering technology
such as inclined dewatering screws or belt filter presses can also be
used. De-watered solids 25 are discharged into a cone bottom receiving
hopper 26. A jet transfer pump 27 at the base of the cone 28 of the
receiving hopper 26 mixes the solids with the heated solvent stream from
line 29 to produce the heated slurry mixture in line 30 which is passed
into the first hydrocyclone separator 31. Centrifugal forces within the
first hydrocyclone separator 31 separate a large portion of the solids
from the oil and solvent mixture. The solids are removed from the bottom
of hydrocyclone separator 31 and gravity discharged into the cone bottom
hopper 32. The remaining slurry mixture, comprised primarily of the oil
and solvent, in line 33, is gravity discharged into the centrate
collection tank 34. Any residual solids in this stream settle to the
bottom of the centrate collection tank 34. The oil and solvent are
separated from the top of centrate collection tank at point 35. The jet
transfer pump 36 located at the respective base 37 of the centrate
collection tank 35 mixes the solids with the heated solvent stream in
line 38 and passes it through line 39 to the second hydrocyclone
separator 40. Centrifugal forces within the second hydrocyclone separator
40 separates the remaining portion of the solids from the oil and solvent
mixture. The solids are removed from the bottom of hydrocyclone separator
40 and gravity discharged into the cone bottom hopper 32. Optionally, the
solvent wash step can be repeated multiple times with each step identical
to the preceding step.

[0019]Referring to FIG. 1C, solids that are deposited in cone bottom
hopper 32 are removed via jet pump 41 at base 42 and de-watered by
centrifuge 43, preferably using a basket or solid bowel centrifuge. Other
alternative mechanical dewatering technology can be used such as inclined
dewatering screws and or belt filter presses. De-watered solids 44 are
gravity discharged into a cone bottom receiving hopper 45. Jet transfer
pump 46 at the base of the cone 47 of the receiving hopper 45 mixes the
de-watered solids with the hot water stream from line 48 to produce the
hot slurry mixture in line 49 which is passed into a hydrocyclone
separator 50. Centrifugal forces within the first hydrocyclone separator
50 separate a large portion of the solids from the oil and water mixture.
The solids are removed from the bottom of hydrocyclone separator 50 and
gravity discharged into cone bottom hopper 51. The remaining slurry
mixture, comprised of the oil and water, in line 52, is gravity
discharged into centrate collection tank 53. The solids settle to the
bottom of the centrate collection tank 53. The oil and water are removed
from the top at point 54 of the centrate collection tank. Jet transfer
pump 55 located at base 56 of centrate collection tank 54 removes and
mixes the solids with the hot water stream in line 57 and passes it
through line 58 to a second hydrocyclone separator 59. Centrifugal forces
within the second hydrocyclone separator 59 separate the remaining
portion of the solids from the oil and water mixture. The solids are
removed from the bottom of hydrocyclone separator 59 and gravity
discharged into the cone bottom hopper 51. Optionally, the hot water wash
step can be repeated multiple times with each step identical to the
preceding step. As a further option, the solids collected from cone
bottom hopper 51, mostly clays and silts, can be further treated by
further thickening then fed into a thermal screw. There, the solids may
be mixed with calcium oxide. The use of calcium oxide is contemplated in
an embodiment of the invention to chemically condition the solids.
Calcium oxide addition is to coagulate the solids to release sorbed
water, which if added in sufficient concentration will locally increase
the temperature of the solids, coupled with the heat input form the other
direct and indirect heating systems can cause the water and any residual
hydrocarbons to vaporize. The thermal screw may be equipped with a vapour
recovery system since the reaction would be exothermic. A dry solids
stream is produced after the oxidation of any remaining hydrocarbons in
the clay and silt slurry.

[0020]Solids that are deposited in the cone bottom hopper 51 are removed
via jet pump 60 at the base 61 and mixed with hot water stream in line 62
and passes it through line 63 the inlet of centrifuge 64 preferably using
a basket or solid bowel centrifuge. Other alternative mechanical
dewatering technology can be used such as inclined dewatering screws
and/or belt filter presses. De-watered solids 65 can be optionally
discharged into receiving pile 66 or alternatively discharged into cone
bottom receiving hopper 67 for thermal treatment. Solids requiring
additional thermal treatment for treatment and recovery of any residual
hydrocarbons or alternatively for further drying are to be blended and
mixed with calcium oxide in a controlled manner directly within the
thermal screw at the inlet point of the thermal screw. Mixing calcium
oxide with moist solids chemically reacts with the moisture associated
with the solids to locally increase the temperature of solids through
direct heating caused by the exothermic reactions, causing both moisture
and residual hydrocarbons to vaporize. The mix ratio of calcium oxide is
a function of the desired temperature increase, which to achieve can
require the addition of water to the solids in hopper 67. Residual
de-watered solids, consisting of the clays and silts recovered from the
wastewater treatment process can be discharged via line 68 into the cone
bottom receiving hopper 67 for thermal treatment.

[0021]Referring in particular to FIG. 1E, subsequently, and optionally, a
thermal screw 69 may be used to treat a portion of the entire solids
fraction for removal of any residual hydrocarbons or alternatively for
further drying. The thermal screw 69 is configured to contemplate the
direct and indirect heating of the solids for treatment by exposing the
solids directly to direct heat produced through the addition of calcium
oxide and through the addition of either hot exhaust gases from a
combustion engine or alternatively a hot inert gas. Calcium oxide is to
be metered directly into the thermal screw at the inlet point for
blending and mixing with the solids. Indirect heating is provided by the
heater system 73 which can consist of the heating of the outside trough
surface of the thermal screw using electric heaters, or an outside jacket
designed to receive and circulate hot oil or alternatively steam for
contact with the surface. A rotary valve 70 at the base of cone 71 of the
receiving hopper 67 meters the de-watered solids into the thermal screw
69. A rotary valve (not shown) at the base of cone 174 meters calcium
oxide into the solids fraction as it enters the thermal screw 67. Both
rotary valves are equipped with a variable frequency drive to provide
operational control of the feed input. The thermal screw 69 preferably
consists of a screw conveyor complete with a gas manifold collection
system 72, heating system 73, cooler 74, gas-liquid separator 75, blower
76, inert gas storage system 77, and inert gas recycle system at point
78. The de-watered solids are introduced into the thermal screw at point
69. Hot inert gas from the inert gas recycle system 78 or alternatively
the hot exhaust gases from a combustion engine (not shown) is introduced
into the thermal screw using a rotary swivel at 79 via line 80. Prior to
introduction into the thermal screw 69 the inert gas is indirectly heated
to the operating temperature of the thermal screw through the wrapping of
the inert gas line 81 between the heater system 73 and body of the
thermal screw 82. In the case where hot exhaust gases are used, the gases
can be injected directly into the thermal screw without indirect
pre-heating of the gases. Hot gases 83 from within the thermal screw 69
consisting principally of vaporized hydrocarbons and water vapor are
removed under a vacuum in the case where an inert gas storage supply is
used or alternatively under positive pressure in the case where hot
exhaust gases from a combustion engine are used for direct heating and
the maintaining of a non-oxidizing environment within the thermal screw
from the thermal screw via line 84 at multiple gas discharge ports on top
of the screw housing shown at the respective locations 85, 86 and 87.

[0022]The hot gases removed from the thermal screw via line 84 are
separated into two gas streams at point 88. Hot gases in line 89 are
passed into the water knockout drum 90 for water removal after which the
gases pass through line 91 to the fuel inlet system of the gas fired
co-generation unit 92.

[0023]Hot gases in line 93 are passed into the cooler at point 94, where
the hot gas mixture is cooled using an air cooler 74. Alternatively, a
chiller may be used instead. Exiting via line 95 from the cooler 74 is a
cooled multi-phase mixture consisting of the inert gas and liquid
droplets of oil and water. The mixture enters the gas-liquid separator 75
at point 96 where the condensate is separated from the inert gas. The
inert gas exits the gas-liquid separator 75 via line 98.

[0024]Blower 76 preferably a rotary lobe blower withdraws the hot gases
from the thermal screw under a vacuum or positive pressure depending on
the source and nature of the hot gases used for direct heating and
maintenance of the non-oxidizing environment. The blower is equipped with
a variable speed drive to control the vacuum pressure under which the
thermal screw 69 is operated.

[0025]The inert gas is discharged from the blower 76 via line 99, where at
point 101, the line is split into two gas streams shown via lines 102 and
103. Control valves 104 and 105 and gas flow meter 106 regulate the inert
gas flow that is recycled to the thermal screw 69. Inert gas via line 107
and recycled gas 108 are indirectly heated using the hot outside surface
of the thermal screw housing before entering the swivel connection at 78
of the holoflyte screw auger of the thermal screw. Excess exhaust gas,
via line 102, enters a vapor recovery unit 109 where the gas is further
chilled to remove any residual hydrocarbons and vaporized metals. The
inert gas is discharged from the vapor recovery system via line 110 to
the atmosphere at point 111. Optionally the entire inert gas stream via
line 99 can be recycled via line 103 or alternatively discharged via line
102 to be processed by the vapor recovery unit 109 as would be the case
for hot exhaust gases utilized from a combustion engine for direct
heating.

[0026]Referring in particular to FIG. 1D, oily materials separated by
hydrocyclone separators 10, 19, 31, 40, 50 and 59 and discharged into
centrate collection tanks 13, 34 and 53 via lines 12, 33, and 52 are
treated separately for the recovery of bitumen oil for the different
oil-water mixtures via lines 112 and 114 and oil-solvent mixture streams
via line 113. All, or a portion of all, the solids fraction de-watered
using the centrifuges 115 and 116 are gravity discharged into the feed
hoppers 45 and 67 of the thermal screw 69. The oil-water fraction of the
oily material deposited in centrate collection tank 13 overflows via line
112 into a floatation unit 175. Air is introduced via a line 176 into the
floatation unit 175 through fine bubble diffusers at 117 to produce fine
bubbles to float and concentrate the bitumen oil to produce a froth which
discharges via line 118 into the oil-water separator 119.

[0027]The concentrated oil-water mixture is removed at point 120 of the
floatation unit 175 and passed via line 118 to the oil/water separator
119. The oil water separator 119 separates the oil from the water, with
the oil removed via line 121 and passed into the oil storage tank 122.
The water is removed via line 123 which then interconnects with line 124
to form line 125 which is passed into the rapid mix tank 126.

[0028]The water mixture enters the rapid mix tank 126 where it is treated
with the primary coagulant 127 introduced via a line into the mix tank
128. Synthetic polymers are the preferred coagulant, but metal-based
coagulants can also be used. The treated water mixture exits the rapid
mix tank 126 via line 129 and enters into the flocculation unit 130. The
treated water mixture flows through a series of baffled slow mix chambers
equipped with slow rotating mechanical mixers. Residual particles in the
water mixture are coagulated and agglomerated within the flocculation
unit.

[0029]The coagulated water exists the flocculation unit 130 via line 131
and enters into the sedimentation tank 132. The coagulated solids are
gravity settled in the sedimentation tank 132. The jet pump 133 at the
base 134 of the sedimentation tank 132 removes and transfers the
coagulated solids via line 135 to the mechanical de-watering unit 116,
preferably a basket or solid bowel centrifuge. The de-watered solids
exits the centrifuge via line 136 and are transferred to the cone bottom
receiving hopper 67 of the thermal screw 69.

[0030]Referring in particular to FIG. 1F, the water from the sedimentation
tank 132 overflows via a weir at point 137 and is discharged via line 138
to the surge tank 139. From surge tank 139 the water is pumped via line
140 into the filtration unit 141 for the removal of any residual solids
carryover from the sedimentation tank 132. Residual solids are captured
within filtration unit 141. The clarified water exits the filtration unit
141 via line 142 and enters the storage tank 143. From the storage tank
water enters the vacuum filtration unit 144.

[0031]Optionally, the filter unit 141 and vacuum filtration unit 144 may
be by-passed via line 145 with the clarified water directly recycled via
line 146 to the water storage tank 147.

[0032]Clarified water via line 148 enters the vacuum filtration unit 144
where it is heated under a vacuum to produce distilled water. Distilled
water exits via line 149 from the vacuum filtration unit 144 where it is
pumped to the water storage tank 147. The brine concentrate containing
the impurities is discharged from the vacuum filtration unit 144 via line
150 into the concentrate tank 151 for disposal. Optionally, the
concentrate can be recycled back to the vacuum filtration unit using a
control loop that relies on the resultant brine concentration for
additional distillation to recover as much as distilled water as
possible.

[0033]With reference to FIG. 2, the operation of a preferred feed hopper,
jet pump and hydrocyclone is described in further detail. The tar sands
material is first deposited into feed hopper 152 that has an elongated
trough at its base within which lies an auger 153. The tar sands material
is then augured with auger 153 to the inlet of the jet pump 154. A
pressurized wash fluid 155 is fed to the inlet nozzle 156 of the jet pump
154 using a conventional centrifugal pump (not shown). The jet pump inlet
nozzle 156 directs a flow into the mixer 157 educting the tar sands into
the jet pump 154 where extreme turbulence and mixing occurs at point 158.
The slurry flow slows in velocity in the diffuser 159. The slurry then
flows into an engineered pipeline 160 of a sufficient length required to
optimize separation for the wash fluid used from where it enters the
entrance of the hydrocyclone 161. A centrifugal force is created in the
upper chamber 162 of the hydrocyclone. The solids are forced to the
outside of the hydrocyclone at point 163 and the wash fluid and bitumen
are forced to the center of the hydrocyclone at point 164. The solids
exit the hydrocyclone at the vortex 165 as an underflow. The wash fluid
and bitumen exit the hydrocyclone as an overflow at point 166 at the top
of the hydrocyclone. The wash fluid and bitumen are transported in a
flexible pipeline 167 to the next phase which can be a repeat of the
first step.

[0034]With reference to FIG. 3, the operation of the jet pump 154 (FIG. 2)
is described in further detail. Unlike other pumps, a jet pump has no
moving parts. A typical jet pump consists of the following: a jet supply
line 168, a nozzle 169, a suction chamber 171, a mixing chamber 172 and a
diffusor 173 leading to a discharge line. In a jet pump, pumping action
is created as a fluid (liquid, steam or gas) passes at a high pressure
and velocity through the nozzle 169 and into a chamber 171 that has both
an inlet and outlet opening. Pressurised wash fluid is fed into the jet
pump 154 (FIG. 2) at jet supply line 168. The wash fluid passes through
inlet nozzle 169, where it meets tar sand material gravity fed from
hopper inlet 170 at the suction chamber 171. The resulting slurry is
mixed and agitated within the mixing chamber 172 where it undergoes an
initial phase separation of oil fraction from solid fraction. The
agitated slurry slows in velocity in the diffuser 173. Upon entry into
the jet pump 154 (FIG. 2), the tar sands material from hopper 152 is
entrained and mixed with the wash fluid from the nozzle 169, which
undergoes a substantial pressure drop across the jet pump 154 (FIG. 2)
and causes extreme mixing of the slurry. The extreme mixing and pressure
drop causes cavitation bubbles to develop on the inside of chamber 171,
which implode on solid particles to enhance the separation of the bitumen
oil from the solid particles.

[0035]The jet pump of the present invention functions as an ejector or an
injector or an eductor, distinct from a venturi pump and an airmover. A
venturi has little in common conceptually with a jet pump. A venturi is a
pipe that starts wide and smoothly contracts in a short distance to a
throat and then gradually expands again. It is used to provide a low
pressure. If the low pressure is used to induce a secondary flow it
becomes a pump, resulting in a loss of pressure in the throat. If the
secondary flow is substantial the loss will be too great to have a
venturi operate like a pump. To operate like a pump it would have to be
redesigned as a jet pump. Venturi pumps have limited capacity in
applications like chemical dosing where a small amount of chemical is
added to a large volume of fluid. A jet pump is a pump that is used to
increase the pressure or the speed of a fluid. Energy is put into the
fluid and then taken out by a different form. In a jet pump energy is
added by way of a high speed jet fluid called the primary flow. In the
design shown in FIG. 3, the primary flow is produced by jet nozzle 169.
Energy is taken out mostly as increased pressure of a stream of fluid
passing through. In a jet pump this stream is called the secondary flow
and it is said to be entrained by the primary flow. A jet pump is
designed to be energy efficient. A venturi pump does not have the
capacity to induce large volumes of flow, where as a jet pump can and
operate energy efficient. Unlike a venturi pump, a jet pump consists of a
nozzle, mixing chamber and diffuser. In a jet pump these components are
specifically engineered to have the pump operate energy efficient. A
venturi pump does not have a defined nozzle, but instead a constriction
in the pipe. It also does not have a defined mixing chamber.

[0036]The wash fluid can be combination of fluids used singularly or in
combination in multiple loops consisting of a chemically treated or
chemical free hot or cold water or alternatively a hot or cold solvent.
The wash fluid can chemically and/or physically react with the bitumen
oil to partition the oil to the liquid phase to permit separation and
recovery by hydrocyclone separation. The continuous supply of wash fluid
by the motive pump provides for the transport of the tar sands carried in
a wash fluid stream to continue the extraction of bitumen from the oil
sands in the pipeline. Hydrocyclone separator 161 is used to classify and
remove the bitumen oil and water fraction from the solids fraction, with
the solid fraction deposited into a second hopper. If necessary, the
solids fraction can be repeatedly treated for additional bitumen recovery
by repeating the process.

Process Conditions

[0037]As the tar sands enter the receiving feed hopper, they are
mechanically ground, preferably using a horizontal shear mixer, to reduce
the solid particles to 25 mm in size or smaller. The motive pump (not
shown), preferably of a centrifugal pump, is configured to draw chemical
free hot water of a temperature at about 95 degrees Celsius from a hot
water tank to produce a high pressure water stream at the inlet of the
jet pump. At the jet pump inlet the high pressure water stream, at
approximately 120 psi, is converted within the jet pump nozzle into a
high velocity water jet, referred to as the primary flow. The substantial
pressure drop within the jet pump draws the slurry mixture from the
hopper, referred to as the secondary flow, into the jet pump where it is
mixed with the primary flow to achieve a resultant percent solids
concentration of 25% or less by volume.

[0038]The optional treatment of the clays and fines, collected after the
solids are collected from the first wash process, would be thickened to
approximately 60% solids before being fed into the thermal screw.

[0039]This invention therefore contemplates the use of jet pumps to effect
separation of oil from solid particles. In some embodiments, this method
distinguishes itself from other processes in that it does not require the
use of elutriation vessels, clarifiers, separators, baths or the like to
condition and or separate the oil and liquids from the solids fraction.
Bitumen separation may be achieved during mixing within the jet pump and
pipeline during transport. No other vessels or technologies are required
to effect separation of bitumen oil from solids. Therefore the process is
substantially simplified in comparison to existing hot water or solvent
bitumen extraction processes. The use of centrifugal forces by way of
hydrocyclones and centrifuges are employed throughout the process for
separation and classification of the different stream fractions
consisting of water, oil, and solids. In accordance with aspects of this
invention, physical, chemical and thermal processes are employed to
separate, treat and recover bitumen oil from solid particles,
irrespective of the oil and solid type and concentration. Direct and
indirect heating of the different medias are provided using a variety of
chemical and chemical free treatment liquid wash and thermal processes to
effect separation of bitumen oil from the solids. Such process strategy
provides for the treatment of all solid particle types, including those
particles of high surface activity consisting of silts and clays, prone
to adsorb and retain oil contamination. Treatment and disposal of the
fines are provided in the process contemplated, maximizing the recovery
of bitumen.

[0040]There are no moving parts contacting the slurry, making this process
less mechanically intensive and subsequently more economical to operate
from a O&M standpoint, compared to other bitumen recovery processes. Each
step of the method is configured and optimized to separate bitumen with
the end process being bitumen recovery.

[0041]The method has application in the processing of tar sands,
production sand, drill cuttings derived from bitumen laden geological
formations using water based drill fluids, contaminated oily sand or
gravel, and contaminated soil.

[0042]Immaterial modifications may be made to the embodiments disclosed
here without departing from the invention.